Science News
Shuttle Discovery prepares for space station rendezvous
By DPA
Dec 11, 2006, 17:30 GMT

Washington - The space shuttle Discovery on Monday prepared to dock with the International Space Station, where shuttle crew members will conduct a complex project to rewire the ISS electricity system and deliver a new station crew member.

The shuttle is due to link up with the station in orbit 400 kilometres above the Earth at 2205 GMT Monday, according to projections by the US space agency NASA.

Shortly before docking, Discovery will do a back-flip manoeuvre so that the crew can examine the shuttle's heat shield to make sure it was not damaged during Saturday's launch.

Earlier inspections found no problems in the heat shield, and NASA's initial analysis of launch film produced no evidence of problems with debris striking the shuttle. The disintegration on re-entry of the shuttle Columbia in 2003 was blamed on a large piece of insulating foam breaking off the external fuel tanks on lift off, and the problem remains a major safety concern.

Discovery lifted off late Saturday from the Kennedy Space Centre at Cape Canaveral, Florida, for construction mission to the ISS, where the shuttle will spend most of its scheduled 12 days in orbit.

The flight's primary mission is to hook up the ISS' permanent electricity-generating system, replacing a temporary power system operating since the space station went into orbit in 1998. Three spacewalks are planned, including two to rewire both halves of the station.

NASA has described Discovery's rewiring mission at the ISS as one of the most complex and difficult in the history of space flight.

Discovery's flight is the second working shuttle mission to the ISS since NASA returned to flight in summer 2005 after the shuttle fleet was grounded for two years following the Columbia disaster, which killed all seven crew members.

NASA spent most of the last year testing new safety systems. A September flight by the shuttle Atlantis marked the resumption of ISS construction.

The flight is the 20th shuttle mission to the space station, the 33rd overall for Discovery and the 117th space shuttle launch since the programme began flying in 1981. With two catastrophic failures in its history, the shuttle fleet is slated to be moth-balled after the scheduled completion of ISS construction in 2010.

Discovery is to deliver astronaut Sunita Williams to replace German astronaut Thomas Reiter after five and a half months in residence on the space station, which has a rotating crew of three astronauts. Reiter, a European Space Agency astronaut due to return to Earth on Discovery, served as flight engineer aboard the ISS, a role that Williams will take over.

The rest of the Discovery crew consists of Commander Mark Polansky, a former US Air Force test pilot; shuttle pilot William Oefelein; mission specialist Robert Curbeam, a veteran of three previous spacewalks; mission specialist Joan Higginbotham, who will operate the ISS robotic arm during construction work; mission specialist Nicholas Patrick; and mission specialist Christer Fugelsang of Sweden, a European Space Agency astronaut who is the first Scandinavian in space.